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81.
Environmental Security: A Geographic Information System Analysis Approach—The Case of Kenya 总被引:2,自引:0,他引:2
Studies into the relationships between environmental factors and violence or conflicts constitute a very debated research
field called environmental security. Several authors think that environmental scarcity, which is scarcity of renewable resources,
can contribute to generate violence or social unrest, particularly within states scarcely endowed with technical know-how
and social structures, such as developing countries. In this work, we referred to the theoretical model developed by the Environmental
Change and Acute Conflict Project. Our goal was to use easily available spatial databases to map the various sources of environmental
scarcity through geographic information systems, in order to locate the areas apparently most at risk of suffering negative
social effects and their consequences in terms of internal security. The analysis was carried out at a subnational level and
applied to the case of Kenya. A first phase of the work included a careful selection of databases relative to renewable resources.
Spatial operations among these data allowed us to obtain new information on the availability of renewable resources (cropland,
forests, water), on the present and foreseen demographic pressure, as well as on the social and technical ingenuity. The results
made it possible to identify areas suffering from scarcity of one or more renewable resources, indicating different levels
of gravity. Accounts from Kenya seem to confirm our results, reporting clashes between tribal groups over the access to scarce
resources in areas that our work showed to be at high risk. 相似文献
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The European WFD (2000/60/EC) requires the assessment of the ecological quality status of water bodies, and gives great importance to the biological components of the ecosystem. A multimetric, fuzzy-based index for the evaluation of environmental quality (FINE: Fuzzy INdex of Ecosystem integrity) has been developed. The FINE index was calculated at 7 sites in the Sacca di Goro and the Valli di Comacchio (Adriatic Sea), where water and sedimentary chemical data were available for the years 2004 and 2005. A significant positive correlation was found between FINE values and dissolved oxygen, while significant negative correlations were observed between FINE values and transparency, nitrogen and phosphorous in the water column, and heavy metals and PCB in the sediments. 相似文献
85.
Chelsey Walden-Schreiner Sebastian Dario Rossi Agustina Barros Catherine Pickering Yu-Fai Leung 《Ambio》2018,47(7):781-793
Managing protected areas effectively requires information about patterns of visitor use, but these data are often limited. We explore how geotagged photos on Flickr, a popular photo-sharing social-media site, can generate hotspot maps and distribution models of temporal and spatial patterns of use in two mountain-protected areas of high conservation value. In Aconcagua Provincial Park (Argentina), two routes to the summit of Aconcagua were used in summer, but most visitors stayed close to the main road, using formal and informal walking trails and the Visitor Centre, while in winter, there was very limited visitation. In Kosciuszko National Park (Australia), alpine walking trails were popular in summer, but in winter, most visitors stayed in the lower altitude ski resorts and ski trails. Results demonstrate the usefulness of social-media data alone as well as a complement for visitor monitoring, providing spatial and temporal information for site-specific and park-level management of visitors and potential impacts in conservation areas. 相似文献
86.
Alcyonium acaule (Cnidaria, Octocorallia) is a common, hard-bottom soft coral in the northwestern Mediterranean Sea. This study describes sexual reproduction and the gamete development cycle of this soft coral. A population at 15–18 m depth in the Marine Protected Area of the Medes Islands (42º02′55″ N, 3º13′30″ E) was sampled from July 1994–August 1995. A. acaule is gonochoristic and a surface brooder, spawning once a year in early summer. The mean diameter of ripe spermatic sacs was 400 ± 91 (SD) μm, and the mean diameter of mature oocytes was 473 ± 37 (SD) μm. There were 30 spermatic sacs polyp?1 in males and 14 oocytes polyp?1 in females. Different phases of gametogenesis in female and male colonies were examined separately with respect to seasonal changes in bottom temperature and solar irradiance. The data suggest that the relatively constant temperatures in January–April are probably not related to oocyte maturation, but that rising temperatures in May could affect sperm maturation. Rapidly increasing solar irradiance in March may be the trigger for vitellogenesis and oocyte maturation, although the mechanism for this in anthozoans is not understood. 相似文献
87.
Patrizia Sadocco Silvia Nocerino Ernestina Dubini-Paglia Alberto Seves Graziano Elegir 《Journal of Polymers and the Environment》1997,5(1):57-65
An extracellular poly(3-hydroxybutyrate) (PHB) depolymerase was purified fromAureobacterium saperdae cultural medium by using hydrophobic interaction chromatography. The isolated enzyme was composed of a single polypeptide
chain with a molecular mass of 42.7 kDa as determined by SDS-PAGE and by native gel filtration on TSK-HW-55S. The enzyme was
not a glycoprotein. Its optimum activity occurred at pH 8.0 and it showed a broad pH stability, ranging from pH 3 to pH 11.N-Bromosuccinamide and 2-hydroxy-5-nitrobenzyl bromide completely inactivated the enzyme, suggesting the involvement of tryptophan
residues at the active site of the protein. The enzyme was very sensitive to diisopropyl fluorophosphate and diazo-dl-norleucine methyl ester, showing the importance of serine and carboxyl groups. The modification of cysteine residues byp-hydroxy mercuricbenzoate did not cause a loss of activity, whereas dithiothreitol rapidly inactivated the enzyme, revealing
the presence of disulfide bonds.A saperdae depolymerase acted on the surface layer of PHB films and the degradation proceeded by surface erosion releasing monomers
and dimers of 3-hydroxybutric acid. The degradation of PHB films byA. saperdae depolymerase was partially inhibited in the presence of excess amounts of enzyme. This phenomenon, already observed by Mukaiet al. with poly(hydroxyalkanoates) depolymerases fromAlcaligenes faecalis, Pseudomonas pickettii, andComamonas testosteroni, was analyzed according to the kinetic model proposed by these authors. The experimental data evidenced a general agreement
with the kinetic model, although higher initial degradation rates were found withA. saperdae depolymerase. 相似文献
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To understand the consequences of the invasion of the nonnative rainbow trout Oncorhynchus mykiss on the native marble trout Salmo marmoratus, we compared two distinct headwater sectors where marble trout occur in allopatry (MTa) or sympatry (MTs) with rainbow trout
(RTs) in the Idrijca River (Slovenia). Using data from field surveys from 2002 to 2009, with biannual (June and September)
sampling and tagging from June 2004 onwards, we analyzed body growth and survival probabilities of marble trout in each stream
sector. Density of age-0 in September over the study period was greater for MTs than MTa and very similar between MTs and
RTs, while density of trout ≥age-1 was similar for MTa and MTs and greater than density of RTs. Monthly apparent survival
probabilities were slightly higher in MTa than in MTs, while RTs showed a lower survival than MTs. Mean weight of marble and
rainbow trout aged 0+ in September was negatively related to cohort density for both marble and rainbow trout, but the relationship
was not significantly different between MTs and MTa. No clear depression of body growth of sympatric marble trout between
sampling intervals was observed. Despite a later emergence, mean weight of RTs cohorts at age 0+ in September was significantly
higher than weight of both MTs and MTa. The establishment of a self-sustaining population of rainbow trout does not have a
significant impact on body growth and survival probabilities of sympatric marble trout. The numerical dominance of rainbow
trout in streams at lower altitudes seem to suggest that while the low summer flow pattern of Slovenian streams is favorable
for rainbow trout invasion, the adaptation of marble trout to headwater environments may limit the invasion success of rainbow
trout in headwaters. 相似文献